Mobile power system with multiple dc-ac converters and related platforms and methods

ABSTRACT

A mobile power system may include AC-DC converter configured to convert a grid AC signal to a power limited DC charging signal, a DC-AC converter coupled to the AC-DC converter, and a battery module configured to provide a DC power signal. The mobile power system may include a switching circuit coupled between the battery module, and the AC-DC converter and the DC-AC converter. The switching circuit may have a switch, and first and second diodes coupled in parallel to the switch. The mobile power system may include a controller coupled to the battery module, the switching circuit, and the DC-AC converter. The controller may be configured to selectively switch the switching circuit between a first state, a second state, and a third state.

RELATED APPLICATION

This application is based upon prior filed copending Application No.62/775,041 filed Dec. 4, 2018, the entire subject matter of which isincorporated herein by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates to the field of power systems, and, moreparticularly, to mobile vehicle power systems and related methods.

BACKGROUND

The electrical requirements for the automotive, truck, boat andrecreational vehicle industry have, with few exceptions, becomestandardized using twelve volt direct current (DC) electrical systemsand using one or more twelve volt batteries wired in parallel forstorage. Most vehicles have twelve volt lights, twelve volt startermotor and twelve volt ancillary motors for, such things as windshieldwipers, electric door locks and power windows. The twelve volt systemswork well and twelve volt fractional horsepower motors are ideal forintermittent use as the current draw for these small motors is notgreat. Twelve volt engine starter motors produce very high torque forengine starting, but at a very high current draw, often in the range of400 amps. These motors can only run for a few minutes before they drainthe vehicle battery bank and/or burn up.

The twelve volt base electrical systems in vehicles have precluded thedevelopment of practical and efficient electrically driven equipment,such as air compressors, hydraulic pumps, air conditioners and vacuumsystems to be mounted on service, food trucks, recreational vehicle, orover the road vehicles. Invariably, in applications where the vehicle isladen with these power demands, these devices are either powered by theonboard internal combustion engine of the vehicle or by a separateinternal combustion generator.

Internal combustion approaches are effective in providing the neededenergy for the application, but also come with distinct drawbacks. Firstand foremost, internal combustion approaches are loud and disruptive tosome applications, and the engines must be constantly supplied with fuelthat is inherently dangerous. Additionally, internal combustionapproaches release pollution into the atmosphere and include little ifany environmental controls on the exhaust. Internal combustion enginesalso must undergo routine maintenance to assure reliability.

In some stationary applications (e.g. food trucks), the vehicle's powerdemands can be supplied with grid power (i.e. shore power). In thisapproach, the vehicle has a cord that is plugged into a powerreceptacle, and the vehicle draws power from the grid. Often, theconnection is 240 Volts AC, which is not always readily available.

In some approaches, the vehicle is powered by a grid power cord, agenerator, and a battery pack. When the vehicle is attached to gridpower, the electrical load and battery charging is handled by thatsource. When, as is often the case for mobile applications, there is nogrid power available, the generator provides power. In theseapplications, the batteries, while useful, can only charge or discharge,and when in use are the sole source of power. They typically cannot becharged while they are in use. Conversely, while the generator and/orgrid power are connected, the batteries are being charged and thereforecannot be used at all, and the user winds up being dependent on theunreliable availability of grid power or a problematic generator for anyprolonged power usage.

SUMMARY

Generally, a mobile power system may include an AC-DC converterconfigured to convert a grid AC signal to a power limited DC chargingsignal, at least one DC-AC converter coupled to the AC-DC converter, anda battery module configured to provide a DC power signal. The mobilepower system may include a switching circuit coupled between the batterymodule, and the AC-DC converter and the at least one DC-AC converter.The switching circuit may comprise a switch, and first and second diodescoupled in parallel to the switch. The mobile power system may furtherinclude a controller coupled to the battery module, the switchingcircuit, and the at least one DC-AC converter. The controller may beconfigured to selectively switch the switching circuit between a firststate, a second state, and a third state. The first state may includeone of concurrently charging the battery module using the power limitedDC charging signal and routing the DC power signal to the at least oneDC-AC converter, or providing the DC power signal using the batterymodule without the power limited DC charging signal. The second statemay include charging the battery module using the power limited DCcharging signal and disabling the at least one DC-AC converters, and thethird state may include blocking charging of the battery module androuting the DC power signal to the at least one DC-AC converter.

Additionally, the switching circuit may include a current limitingelement coupled between the battery module and the second diode. Thefirst diode may have an anode terminal coupled to a cathode terminal ofthe second diode.

In some embodiments, the at least one DC-AC converter may comprise afirst DC-AC converter configured to generate a first AC power signal,and a second DC-AC converter configured to generate a second AC powersignal. The second AC power signal may have a voltage level less thanthat of the first AC power signal. The mobile power system may furtherinclude first and second AC distribution circuits respectively coupledto the first DC-AC converter and the second DC-AC converter. Each of thefirst and second AC distribution circuits may be configured to deliver aplurality of AC signals respectively to a plurality of loads.

For example, the plurality of loads may have a cumulative power ratinggreater than 4.8 kW. The controller may include a battery managementdevice configured to monitor a plurality of parameters related to thebattery module. The plurality of parameters comprises a total voltagevalue, voltage values of individual battery cells, a temperature value,a state of charge (SOC) value, a state of health (SOH) value, and acurrent value, for instance. Also, the grid AC signal may include a100-250 Volt AC signal, and the DC power signal may comprise a 12-17Volt DC signal.

Another aspect is directed to a mobile vehicle platform. The mobilevehicle platform may include a vehicle body, and a mobile power systemcarried by the vehicle body. The mobile power system may comprise anAC-DC converter configured to convert a grid AC signal to a powerlimited DC charging signal, at least one DC-AC converter coupled to theAC-DC converter, and a battery module configured to provide a DC powersignal. The mobile power system may include a switching circuit coupledbetween the battery module, and the AC-DC converter and the at least oneDC-AC converter. The switching circuit may include a switch, and firstand second diodes coupled in parallel to the switch. The mobile powersystem may include a controller coupled to the battery module, theswitching circuit, and the at least one DC-AC converter. The controllermay be configured to selectively switch the switching circuit between afirst state, a second state, and a third state. The first state mayinclude one of concurrently charging the battery module using the powerlimited DC charging signal and routing the DC power signal to the atleast one DC-AC converter, or providing the DC power signal using thebattery module without the power limited DC charging signal. The secondstate may include charging the battery module using the power limited DCcharging signal and disabling the at least one DC-AC converter, and thethird state may include blocking charging of the battery module androuting the DC power signal to the at least one DC-AC converter. Themobile vehicle platform may include a plurality of loads carried by thevehicle body and powered by the mobile power system.

Yet another aspect is directed to a method for making a mobile powersystem. The method may comprise coupling an AC-DC converter configuredto convert a grid AC signal to a power limited DC charging signal,coupling at least one DC-AC converter to the AC-DC converter, andcoupling a battery module configured to provide a DC power signal. Themethod may further comprise coupling a switching circuit between thebattery module, and the AC-DC converter and the at least one DC-ACconverter. The switching circuit may include a switch, and first andsecond diodes coupled in parallel to the switch. The method may includecoupling a controller to the battery module, the switching circuit, andthe at least one DC-AC converter. The controller may be configured toselectively switch the switching circuit between a first state, a secondstate, and a third state. The first state may include one ofconcurrently charging the battery module using the power limited DCcharging signal and routing the DC power signal to the at least oneDC-AC converter, or providing the DC power signal using the batterymodule without the power limited DC charging signal. The second statemay include charging the battery module using the power limited DCcharging signal and disabling the at least one DC-AC converter, and thethird state may include blocking charging of the battery module androuting the DC power signal to the at least one DC-AC converter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a mobile vehicle platform, according tothe present disclosure.

FIG. 2 is a schematic diagram of a mobile power system, according to afirst embodiment the present disclosure.

FIG. 3 is a schematic diagram of a mobile power system, according to asecond embodiment the present disclosure.

FIG. 4 is a schematic diagram of a mobile power system, according to athird embodiment the present disclosure.

DETAILED DESCRIPTION

The present disclosure will now be described more fully hereinafter withreference to the accompanying drawings, in which several embodiments ofthe invention are shown. This present disclosure may, however, beembodied in many different forms and should not be construed as limitedto the embodiments set forth herein. Rather, these embodiments areprovided so that this disclosure will be thorough and complete, and willfully convey the scope of the present disclosure to those skilled in theart. Like numbers refer to like elements throughout, and base 100reference numerals are used to indicate similar elements in alternativeembodiments.

Referring initially to FIG. 1, a mobile vehicle platform 10 according tothe present disclosure is now described. The mobile vehicle platform 10illustratively includes a vehicle body 13, and a mobile power system 12carried by the vehicle body. In the illustrated embodiment, the vehiclebody 13 is a recreational vehicle. Of course, in other embodiments, thevehicle body 13 may comprise a trailer, a food truck vehicle, or amobile entertainment vehicle, such a mobile escape room.

The mobile vehicle platform 10 illustratively includes a plurality ofloads 11 a-11 d carried by the vehicle body 13 and powered by the mobilepower system 12. For example, the plurality of loads 11 a-11 d maycomprise an air compressor, lighting devices, 12 Volt lighting, games,hydraulic pumps, video screens, air conditioning units, and computingequipment.

The mobile power system 12 illustratively includes one or more AC-DCconverters 17-18 (second converter is optional and indicated with dashedlines), a grid power connection 21, and a retractable cable 22 coupledbetween the one or more AC-DC converters and the grid power connection.The mobile power system 12 illustratively includes a switching circuit14 coupled to the one or more AC-DC converters 17-18, a battery module15 coupled to the switching circuit, and a controller 16 coupled to theswitching circuit and the battery module.

In some embodiments, the battery module 15 may comprise a bank ofLithium Ion battery cells. Each of the one or more AC-DC converters17-18 may comprise one or more of an AC to DC converter, a DC to ACconverter, or a bidirectional AC-DC converter.

The controller 16 is configured to cooperate with the switching circuit14 to control the flow of current into and from the battery module 15.Advantageously, the switching circuit 14 may enable the battery module15 to both be charged and provide power for the mobile vehicle platform10. It should be appreciated that the mobile vehicle platform 10 shownin FIG. 1 is an illustrative example, and the mobile vehicle platformmay comprise the mobile power system embodiments 112, 212, 312 (SeeFIGS. 2-4) disclosed herein.

Although not shown, the mobile power system 12 may comprise a commandinterface coupled to the controller 16. The command interface mayinclude a plurality of command functions for the user to controloperation of the mobile power system 12. Also, the command interface mayinclude a status dashboard providing the current operating state of themobile power system 12. For example, the command interface may comprisea Raspberry Pi microcontroller, as available from the Raspberry PiFoundation of Cambridge, United Kingdom. Also, in some embodiments, thecommand interface may be accessible via a local wireless area network(WLAN) connection. Indeed, in some embodiments, the user may use anassociated mobile wireless communications device to monitor and/orcontrol the command interface mobile power system 12.

Referring now additionally to FIG. 2, another embodiment of the mobilepower system 112 is now described. In this embodiment of the mobilepower system 112, those elements already discussed above with respect toFIG. 1 are incremented by 100 and most require no further discussionherein. This embodiment differs from the previous embodiment in thatthis mobile power system 112 illustratively includes an AC-DC converter117 configured to convert a grid AC signal to a power limited DCcharging signal, and a DC-AC converter 118 coupled to the AC-DCconverter. In this embodiment, the grid power connection 121illustratively includes a standard 120 Volt AC plug (e.g. power limitedto 13 Amp maximum).

The mobile power system 112 illustratively includes a battery module 115configured to provide a DC power signal, and a switching circuit 114coupled between the battery module, and the AC-DC converter 117 and theDC-AC converter 118. The switching circuit 114 illustratively includes afirst switch 125, and a first diode 128 coupled in parallel to the firstswitch.

It should be noted that the first diode 128 is optional. In embodimentsthat include the first diode 128, the DC-AC converter 118 may comprise atwo-way converter (i.e. it can convert AC to DC additionally), and iscoupled to a 220 Volt AC input.

Moreover, the switching circuit 114 illustratively includes a seconddiode 130 coupled to the first diode 128, a second switch 126 coupled inparallel to the second diode, and a third switch 124 and a resistor 123coupled in series. The third switch 124 and the resistor 123 areillustratively coupled in parallel to the first switch 125 and thesecond switch 126. The switching circuit 114 illustratively includes acurrent limiting element 127 (e.g. 150 Amp fuse/circuit breaker) coupledbetween the battery module 115 and the second switch 126. Also, thefirst diode 128 and the second diode 130 have respective cathodeterminals coupled together, and also coupled between the first switch125 and the second switch 126.

The mobile power system 112 illustratively includes a controller 116coupled to the battery module 115 and the switching circuit 114. Thecontroller 116 is configured to selectively switch the switching circuit114 between a first state, a second state, and a third state based upona threshold voltage value from the battery module. The first statecomprises alternatively one of concurrently charging the battery module115 using the power limited DC charging signal and routes the DC powersignal to the DC-AC converter 118, or providing the DC power signalusing the battery module 115 without the power limited DC chargingsignal, i.e. when grid power in unavailable. In other words, the firststate is normal operation, and in the first state, the first, second,and third switches 124-126 are all closed.

The second state relates to a battery under voltage condition (i.e. oneor more of the voltage values of individual battery cells or the totalvoltage value is less than the minimum threshold voltage value). Here,the second state comprises charging the battery module 115 using thepower limited DC charging signal and blocking the DC power signal to theDC-AC converter. In other words, the battery module 115 is charged only,and there is no discharge. In particular, the controller 116 isconfigured to open the first switch 125 in the second state then after50 mS open the third switch 124. Switching in this manor limits themaximum current and voltage that the opening switch will be exposed to.Thus extending the life of the switch. When sufficient charge has beendelivered to the battery module 115 switch 124 closes then after 2seconds switch 125 closes returning to the first state.

The third state relates to a battery overvoltage condition (i.e. one ormore of the voltage values of individual battery cells or the totalvoltage value is greater than the maximum threshold voltage value). Thethird state comprises blocking charging of the battery module 115 androuting the DC power signal to the DC-AC converter 118. In other words,the battery module 115 is discharged only, and there is no charging. Inparticular, the controller 116 is configured to open the second andthird switch 126 and 124 in the third state, and 125 switch remainclosed.

In the illustrated embodiment, the mobile power system 112 furthercomprises an AC distribution circuit 120 coupled to the DC-AC converter118 and configured to deliver a plurality of AC signals respectively toa plurality of loads 111 a-111 e. The plurality of loads 111 a-111 e mayhave a cumulative power rating greater than 4.8 kW.

In the illustrated embodiment, the controller 116 comprises a batterymanagement device configured to monitor a plurality of parametersrelated to the battery module 115. For example, the plurality ofparameters may comprise a total voltage value, voltage values ofindividual battery cells (i.e. are in normal operating range), atemperature value, a SOC value, a SOH value, and a current value. Thegrid AC signal may comprise a 100-250 Volt AC signal, and the DC powersignal may comprise a 40-59 Volt DC signal. The controller 116 alsoincludes logic circuitry to control the state of the first, second, andthird switches 124-126.

In the illustrated embodiment, the mobile power system 112 furthercomprises of a current monitor 147 c configured to monitor current drawfrom the grid power connection 121, thereby preventing tripping a loadprotection element within the grid power connection (i.e. a circuitbreaker). The plurality of current monitors 147 a-147 b is configured tomonitor a current load going into the AC distribution circuit 120. Eachof the plurality of current monitors 147 a-147 c comprises an activecurrent monitor providing instant feedback to prevent excessive currentdraw.

Yet another aspect is directed to a method for making a mobile powersystem 112. The method includes coupling an AC-DC converter 117configured to convert a grid AC signal to a power limited DC chargingsignal, and coupling a DC-AC converter 118 to the AC-DC converter. Themethod includes coupling a switching circuit 114 between a batterymodule 115, and the AC-DC converter 117 and the DC-AC converter 118. Thebattery module 115 configured to provide a DC power signal. Theswitching circuit 114 includes a first switch 125, and a first diode 128coupled in parallel to the first switch. The method also comprisescoupling a controller 116 to the battery module 115 and the switchingcircuit 114. The controller 116 is configured to selectively switch theswitching circuit 114 between a first state and a second state. Thefirst state concurrently charges the battery module 115 using the powerlimited DC charging signal and routes the DC power signal to the DC-ACconverter 118, and the second state provides the DC power signal usingthe battery module without the power limited DC charging signal.

Advantageously, the mobile power system 112 permits the battery module115 to handle all peak loads while a 120v variable amperagecharger-transformer 121 sends a stream of constant current back into thesystem, supplementing the battery's usage. In an exampleembodiment/implementation of the mobile power system 112, over thecourse of a 6, 8, 10 hour work day, the charger increased the life ofthe battery module 115 by between 50-100%, depending largely on the airconditioning compressor's load.

Referring now additionally to FIG. 3, another embodiment of the mobilepower system 212 is now described. In this embodiment of the mobilepower system 212, those elements already discussed above with respect toFIGS. 1-2 are incremented by 200 and most require no further discussionherein. This embodiment differs from the previous embodiment in thatthis mobile power system 212 illustratively includes an AC-DC converter217 configured to convert a grid AC signal to a power limited DCcharging signal, and first and second DC-AC converters 218 a-218 bcoupled to the AC-DC converter.

The mobile power system 212 illustratively includes a battery module 215configured to provide a DC power signal, and a switching circuit 214coupled between the battery module, and the AC-DC converter 217 and thefirst and second DC-AC converters 218 a-218 b. In this embodiment, thegrid power connection 221 illustratively includes a standard 120 Volt ACplug (e.g. power limited to 13 Amp maximum or 1560 watts).

The mobile power system 212 illustratively includes a controller 216coupled to the battery module 215, the switching circuit 214, and thefirst and second DC-AC converters 218 a-218 b. The controller 216 isconfigured to selectively switch the switching circuit 214 between afirst state, a second state, a third state, and a fourth state. Thefirst state includes one of concurrently charging the battery module 215using the power limited DC charging signal and routing the DC powersignal to the first and second DC-AC converters 218 a-218 b, orproviding the DC power signal using the battery module 215 without thepower limited DC charging signal, i.e. when grid power is unavailable.In other words, the first state relates to normal operation.

The switching circuit 214 illustratively includes a switch 233, a firstdiode 231, and a second diode 232. The first diode 231 and the seconddiode 232 are coupled in parallel to the switch 233. Additionally, theswitching circuit 214 includes a current limiting element (e.g. 500 Ampfuse/circuit breaker) coupled between the battery module 215 and thesecond diode 232. The first diode 231 illustratively includes an anodeterminal coupled to a cathode terminal of the second diode 232, i.e.they are coupled in series.

In the illustrated embodiment, the first DC-AC converter 218 a isconfigured to generate a first AC power signal, and the second DC-ACconverter 218 b is configured to generate a second AC power signal.Here, the second AC power signal (e.g. 120 Volt AC) has a voltage levelless than that of the first AC power signal (e.g. 220 Volt AC). Themobile power system 212 illustratively includes first and second ACdistribution circuits 222 a-220 b respectively coupled to the firstDC-AC converter and the second DC-AC converter 218 a-218 b.

Each of the first and second AC distribution circuits 220 a-220 b isconfigured to deliver a plurality of AC signals respectively to aplurality of loads 211 a-211 b & 211 c-211 d. For example, the pluralityof loads 211 a-211 b & 211 c-211 d may have a cumulative power ratinggreater than 4.8 kW.

Also, in this embodiment, similar to the embodiment of FIG. 2, thecontroller 216 includes a battery management device configured tomonitor a plurality of parameters related to the battery module. Also,the grid AC signal may include a 100-250 Volt AC signal, and the DCpower signal may comprise a 12-17 Volt DC signal.

Also, the mobile power system 212 illustratively includes a cutoffswitch 244 coupled to the controller 216. Depending on the values of theplurality of parameters (i.e. if a cell voltage is over the maximumthreshold limit), the controller 216 may disconnect the grid AC signal.In other words, the controller 216 can island the mobile power system212 if needed for safety.

The second state relates to a battery under voltage condition (i.e. oneor more of the voltage values of individual battery cells or the totalvoltage value is less than the minimum threshold voltage value). Here,the second state comprises charging the battery module 215 using thepower limited DC charging signal and disabling the first DC-AC converterand the second DC-AC converter 218 a-218 b. In particular, thecontroller 216 is configured to disable the first DC-AC converter andthe second DC-AC converter 218 a-218 b so that the battery module 215 isrecharged without any power draw to the plurality of loads 211 a-211 b &211 c-211 d.

The third state relates to a battery overvoltage condition (i.e. one ormore of the voltage values of individual battery cells or the totalvoltage value is greater than the maximum threshold voltage value). Thethird state comprises comprising blocking charging of the battery module215 and routing the DC power signal to the first DC-AC converter and thesecond DC-AC converter 218 a-218 b. In other words, due to the currenthealth state of the individual batteries in the battery module 215, thecharge current into the battery module must be stopped. Here, thecontroller 216 is configured to open the cut-off switch 244, whichisolates the mobile power system 212 from the grid power connection 221.

The fourth state relates to a supply over voltage for the first DC-ACconverter and the second DC-AC converter 218 a-218 b. In particular, thefirst DC-AC converter and the second DC-AC converter 218 a-218 b eachhave a desired input DC voltage range. In some applications,particularly when the battery module 215 is fully charged and the cellshave their highest charged voltage, the DC power signal outputted to thefirst DC-AC converter and the second DC-AC converter 218 a-218 b isgreater than a desired range, and damage can result. In this state, thecontroller 216 is configured to cause the switch 233 to open. Thisprevents the battery module 215 from providing an over voltage conditionto the DC-AC converters 218 a-218 b a voltage drop in the DC powersignal is provided (via the first and second diodes 231, 232).

Yet another aspect is directed to a method for making a mobile powersystem 212. The method comprises coupling an AC-DC converter 217configured to convert a grid AC signal to a power limited DC chargingsignal, coupling first and second DC-AC converters 218 a-218 b to theAC-DC converter, and coupling a battery module 215 configured to providea DC power signal. The method further comprises coupling a switchingcircuit 214 between the battery module 215, and the AC-DC converter 217and the first and second DC-AC converters 218 a-218 b. The switchingcircuit 214 includes a switch 233, a first diode 231, and a second diode232 coupled in parallel to the switch. The method includes coupling acontroller 216 to the battery module 215, the switching circuit 214, andthe first and second DC-AC converters 218 a-218 b. The controller 216 isconfigured to selectively switch the switching circuit 214 between afirst state and a second state. The first state includes concurrentlycharging the battery module 215 using the power limited DC chargingsignal and routing the DC power signal to the first and second DC-ACconverters 218 a-218 b, and the second state provides the DC powersignal using the battery module 215 without the power limited DCcharging signal. Advantageously, this embodiment may be less expensiveto manufacture, and has reduced size, and weight however it is the lesteffect of embodiments due to 100% of the power goes through the AC-DCconverter 217 and the DC-AC converters 218 a-218 b plus when the batteryis charged more loss is incurred from the voltage dropping diodes231-232.

Referring now additionally to FIG. 4, another embodiment of the mobilepower system 312 is now described. In this embodiment of the mobilepower system 312, those elements already discussed above with respect toFIGS. 1-3 are incremented by 300 and most require no further discussionherein. This embodiment differs from the previous embodiment in thatthis mobile power system 312 illustratively includes a bidirectionalAC-DC converter 317 configured to convert a grid AC signal to a powerlimited DC charging signal with a threshold level (e.g. limited by acircuit breaker associated with the grid AC signal, such as a 15 ampmaximum being the threshold level), and a battery module configured toprovide a DC power signal. In this embodiment, the battery modulecomprises first and second battery modules 315 a-315 b.

The mobile power system 312 illustratively includes first and secondswitching circuits 314 a-314 b coupled between the first and secondbattery modules 315 a-315 and the bidirectional AC-DC converter 317. Themobile power system 312 illustratively includes a controller 316 a-316 bcoupled to the first and second battery modules 315 a-315 b and thefirst and second switching circuits 314 a-314 b.

The controller 316 a-316 b is configured to selectively switch thebidirectional AC-DC converter 317 between a first state, a second state,a third state, and a fourth state. The first state includes, when a loadpower level is less than the threshold level, concurrently charging thefirst and second battery modules 315 a-315 b using the power limited DCcharging signal and delivering the grid AC signal to a plurality ofloads 311 a-311 e. The second state includes, when the load power levelis greater than the threshold level, concurrently converting the DCpower signal with the bidirectional AC-DC converter 317 into a batteryAC signal for delivery to the plurality of loads 311 a-311 e, anddelivering the grid AC signal to the plurality of loads. The third statecomprises, when the first and second battery modules 315 a-315 b arefully charged, and when the load power level is less than the thresholdlevel, delivering the grid AC signal to the plurality of loads 311 a-311e and placing the bidirectional AC-DC converter 317 in a stand-by state.The fourth state comprises when the power limited DC charging signal isunavailable, converting the DC power signal with the bidirectional AC-DCconverter 317 into the battery AC signal for delivery to the pluralityof loads 311 a-311 e.

Each of the first switching circuit 314 a and the second switchingcircuit 314 b illustratively includes a first switch 336, and a diodepair 335 coupled in parallel to the first switch. Each diode of thediode pair 335 comprises a Zener diode, each having respective cathodeterminals coupled together. As will be appreciated, the diode pair 335is coupled as a waveform clipping device. Also, it should be appreciatedthat the diode pair 335 may be omitted in some embodiments.

More specifically, each of the first switching circuit 314 a and thesecond switching circuit 314 b comprises a second switch 338 and aresistor 337 coupled in series, and the second switch and the resistorare coupled in parallel to the first switch 336. Each of the firstswitching circuit 314 a and the second switching circuit 314 billustratively includes a current limiting element 327 a-327 b (e.g. a30 Amp fuse/circuit breaker) coupled between the first and secondbattery modules 315 a-315 b and the first switch 336.

The mobile power system 312 illustratively includes an AC distributioncircuit 320 coupled to the bidirectional AC-DC converter 317 andconfigured to deliver a plurality of AC signals respectively to theplurality of loads 311 a-311 e. The plurality of loads 311 a-311 e mayhave a cumulative power rating greater than 9.6 kW.

Also, as in the embodiments of FIGS. 2-3, the controller 316 a-316 bincludes a battery management device 316 b configured to monitor aplurality of parameters related to the first and second battery modules315 a-315 b. In the illustrated embodiment, the first and second batterymodules 315 a-315 b may provide a total power storage of 10-16 kWh. Inthis embodiment, the controller 316 a and the battery management device316 b are depicted as separate circuits, but in other embodiments, thecircuits may be integrated. The grid AC signal may include a 100-250Volt AC signal, and the DC power signal may comprise a +/−170-227 VoltDC signal, i.e. 314-454 in total.

In this embodiment, the grid power connection 321 illustrativelyincludes a plurality of power inputs providing a corresponding pluralityof grid AC signals. Here, the plurality of grid AC signals comprisefirst and second 240 Volt AC signals (1-50 Amps), and a 120 Volt AC gridAC signal (1-13 Amps). In some embodiments, one or more of the pluralityof grid AC signals can be omitted for power source simplification.

The bidirectional AC-DC converter 317 illustratively includes first andsecond power blocks 334 a-334 b. The first and second power blocks 334a-334 b are independent power blocks. The first power block 334 a isselectively coupled to one or more of the first and second 240 Volt ACsignals, and the 120 Volt AC grid AC signal. The second power block 334b is selectively coupled to one or more of the first and second 240 VoltAC signals. Because of the independence of the first and second powerblocks 334 a-334 b, the mobile power system 312 can utilize multiplegrid power standards with varying phases and voltages simultaneously.

Also, the mobile power system 312 illustratively includes a plurality ofinput cutoff switches 341, 342 a-342 b, 343 a-343 b for each grid ACsignal. If operational or safety concerns necessitate opening of thesecutoff switches 341, 342 a-342 b, 343 a-343 b, the controller 316 a-316b can deactivate (i.e. place in an open state) any one or more of thecutoff switches.

In the off state, the controller 316 a-316 b is configured to cause thefirst switch 336, the second switch 338, and the plurality of inputcutoff switches 341, 342 a-342 b, 343 a-343 b are all set to an openstate. When the mobile power system 312 is powered up, the controller316 a-316 b is configured to review the DC supplies available, if the DCsupply is in the proper voltage range the second switch 338 is closed,then after a delay, the first switch 336 is closed and the second switchis opened. This method limits the DC inrush current. Once the firstswitch 336 is closed, the controller 316 a-316 b is configured to reviewthe AC supplies available (both voltages and the phases) from the gridpower connection 321 and selectively control the plurality of inputcutoff switches 341, 342 a-342 b, 343 a-343 b to provide the mostefficient power source.

Helpfully, the mobile power system 312 includes safeguards for safety,which will shut down once certain parameters are reached. In the eventthat grid AC power is turned off, the grid AC power is disconnected sothat power cannot be sent out through the charging cord, and the firstand second battery modules 315 a-315 b will simply discharge until theyreach a minimum power level limit, shut off, and wait to be chargedagain. In the event of a power outage, when the input source stopssupplying and starts demanding a load (e.g. when a local transformerfails in a storm), the bidirectional AC-DC converter 317 instantaneouslyshuts down the system, disconnects the AC source so power cannot be sentout through the charging cord, and then brings the system back up. Thisis all accomplished within 50 milliseconds, allowing for all systems onthe mobile vehicle platform to stay powered on and functional. Also,there is surge protection built into the bidirectional AC-DC converter317.

Also, the mobile power system 312 illustratively includes a DC-DCconverter 345, and a diode 346 coupled to the DC-DC converter. The DC-DCconverter 345 comprises a step-down converter, which can provide a lowervoltage power source for the controller. The diode 346 is coupledbetween the first switching circuit 314 a and the first battery module315 a.

Yet another aspect is directed to a method for making a mobile powersystem 312. The method comprises coupling a bidirectional AC-DCconverter 317 configured to convert a grid AC signal to a DC powerlimited charging signal, coupling a battery module 315 a-315 bconfigured to provide a DC power signal, and coupling a controller 316a-316 b to the battery module and the bidirectional AC-DC converter andconfigured to selectively switch the bidirectional AC-DC converterbetween a first state and a second state. The first state may include,when a load power level is less than the threshold level, concurrentlycharging the battery module 315 a-315 b using the power limited DCcharging signal and delivering the grid AC signal to the plurality ofloads 311 a-311 e. The second state may comprise, when the load powerlevel is greater than the threshold level, concurrently converting theDC power signal with the bidirectional AC-DC converter 317 into abattery AC signal for delivery to the plurality of loads 311 a-311 e,and delivering the grid AC signal to the plurality of loads.

In any of the mobile power system embodiments 112, 212, 312 notedherein, one or more of the described components may be carried on one ormore circuit boards. Indeed, in some advantageous embodiments, themobile power system could comprise a single circuit board with variousintegrated circuit components thereon.

In these circuit board embodiments, due to the high current nature ofmobile power applications, current may need to be routed off chip or offthe board, and not via conductive traces on the circuit board. In theseapplications, the one or more circuit board include openings adjacentactive components on the circuit boards, and the mobile power systemwould include a plurality of bus bars (e.g. copper bus bar) extendingunder the circuit board. Each bus bar would include one or moreconnection posts to extend through the openings for connection to theactive components on the circuit board (e.g. soldering).

Advantageously, the mobile power system 312 is substantially moreefficient than existing approaches for power conversion. Indeed, thisembodiment is more efficient than the embodiments depicted in FIGS. 2-3.This is due to the elimination of the multiple AC-DC converters,step-down transformers, and rectifiers. The bidirectional AC-DCconverter 317 directs grid AC power without interruption into the mobilevehicle platform, while the first and second battery modules 315 a-315 bhandle all loads in excess of the grid AC power limit.

The mobile power system 312 illustratively includes a plurality ofcurrent monitors 347 a-347 b, 348 a-348 b, and a plurality of voltagemonitors 350 a-350 g. Each of the plurality of current monitors 347a-347 b, 348 a-348 b passes a current value to the controller 316 a-316b. Each of the plurality of voltage monitors 350 a-350 g passes avoltage value to the controller 316 a-316 b.

In some embodiments, additional voltage monitors are located adjacentthe current monitors 347 b, 348 b, and the current limiting elements 327a-327 b. The controller 316 a-316 b uses these current/voltage values tomonitor the real-time load demands and to efficiently route energy inaccordance with a plurality of operational states. The plurality ofoperational states comprises:

-   -   1. directing energy from the grid power connection 321 to a        balanced combination of the plurality of loads 311 a-311 e and        the first and second battery modules 315 a-315 b (load demands        are less than maximum grid power; the first state);    -   2. directing energy from the grid power connection 321 to only        the plurality of loads 311 a-311 e and directing energy        concurrently from the first and second battery modules 315 a-315        b to the plurality of loads 311 a-311 e (load demands are        greater than maximum grid power; combined power mode, second        state).    -   3. directing energy from the grid power connection 321 only to        the plurality of loads 311 a-311 e, and placing the        bidirectional AC-DC converter 317 into a stand-by mode (load        demands meet maximum grid power; or when the first and second        battery modules 315 a-315 b are fully charged and load demands        are less than or equal to maximum grid power);    -   4. grid power connection 321 not available or indicates an        error/problem state, energy from the first and second battery        modules 315 a-315 b is directed to the plurality of loads 311        a-311 e, and the bidirectional AC-DC converter 317 is        disconnected from the grid power connection (battery power only        mode; fourth state).    -   5. directing energy from the grid power connection 321 only to        the first and second battery modules 315 a-315 b (load demands        are near zero; charging mode, e.g. under voltage condition);    -   6. when the bidirectional AC-DC converter 317 or the first and        second battery modules 315 a-315 b generate an error message,        directing energy from the grid power connection 321 only to the        plurality of loads 311 a-311 e and electrically floating the        bidirectional AC-DC converter and the first and second battery        modules (bypass mode, error state); and    -   7. the controller 316 a-316 b causes the first switch 336, the        second switch 338, and the plurality of input cutoff switches        341, 342 a-342 b, 343 a-343 b are all set to an open state (off        state).

If the mobile vehicle platform power load drops below that a limit,power is diverted into the first and second battery modules 315 a-315 bfor recharging. If the first and second battery modules 315 a-315 b arefull, then the load requested of the shore power is below its limit. Inefficient fashion, the bidirectional AC-DC converter 317, in real time,directs or balances the energy from the grid AC signal into the firstand second battery modules 315 a-315 b for charging and into the ACdistribution circuit 320 for driving the needed plurality of loads 311a-311 e.

The mobile power system 312 may achieve an approximate 97% energyefficiency when converting voltages AC-DC or DC-AC. Also, since only afactional amount of the total energy is put though conversion, furtherefficiency is achieved. This gain in conversion efficiency directlycorrelates to a gain in battery life and grid AC efficiency.Additionally, it simultaneously reduces the heat load, which in turnreduces the energy demand from the air conditioning compressor neededmaintain a comfortable temperature. These represent significant energysavings. Finally, the mobile power system 312 is exceptionally small,reducing the cubic footprint and weight.

Other features relating to mobile power systems are disclosed inco-pending applications: titled “MOBILE POWER SYSTEM WITH MULTIPLECONVERTERS AND RELATED PLATFORMS AND METHODS,” Attorney Docket No.0128955; and titled “MOBILE POWER SYSTEM WITH BIDIRECTIONAL AC-DCCONVERTER AND RELATED PLATFORMS AND METHODS,” Attorney Docket No.0129551, all incorporated herein by reference in their entirety.

Many modifications and other embodiments of the present disclosure willcome to the mind of one skilled in the art having the benefit of theteachings presented in the foregoing descriptions and the associateddrawings. Therefore, it is understood that the present disclosure is notto be limited to the specific embodiments disclosed, and thatmodifications and embodiments are intended to be included within thescope of the appended claims.

That which is claimed is:
 1. A mobile power system comprising: analternating current-direct current (AC-DC) converter configured toconvert a grid AC signal to a power limited DC charging signal; at leastone DC-AC converter coupled to said AC-DC converter; a battery moduleconfigured to provide a DC power signal; a switching circuit coupledbetween said battery module, and said AC-DC converter and said at leastone DC-AC converter, said switching circuit comprising a switch, andfirst and second diodes coupled in parallel to said switch; and acontroller coupled to said battery module, said switching circuit, andsaid at least one DC-AC converter, said controller configured toselectively switch said switching circuit between a first state, asecond state, and a third state, the first state comprising one ofconcurrently charging said battery module using the power limited DCcharging signal and routing the DC power signal to said at least oneDC-AC converter, or providing the DC power signal using said batterymodule without the power limited DC charging signal the second statecomprising charging said battery module using the power limited DCcharging signal and disabling said at least one DC-AC converter; thethird state comprising blocking charging of said battery module androuting the DC power signal to said at least one DC-AC converter.
 2. Themobile power system of claim 1 wherein said switching circuit comprisesa current limiting element coupled between said battery module and saidsecond diode.
 3. The mobile power system of claim 1 wherein said firstdiode has an anode terminal coupled to a cathode terminal of said seconddiode.
 4. The mobile power system of claim 1 wherein said at least oneDC-AC converter comprises a first DC-AC converter configured to generatea first AC power signal, and a second DC-AC converter configured togenerate a second AC power signal, the second AC power signal having avoltage level less than that of the first AC power signal.
 5. The mobilepower system of claim 4 further comprising first and second ACdistribution circuits respectively coupled to said first DC-AC converterand said second DC-AC converter, each of said first and second ACdistribution circuits configured to deliver a plurality of AC signalsrespectively to a plurality of loads.
 6. The mobile power system ofclaim 5 wherein the plurality of loads have a cumulative power ratinggreater than 4.8 kW.
 7. The mobile power system of claim 1 wherein saidcontroller comprises a battery management device configured to monitor aplurality of parameters related to said battery module.
 8. The mobilepower system of claim 7 wherein the plurality of parameters comprises atotal voltage value, voltage values of individual battery cells, atemperature value, a state of charge (SOC) value, a state of health(SOH) value, and a current value.
 9. The mobile power system of claim 1wherein the grid AC signal comprises a 100-250 Volt AC signal; andwherein the DC power signal comprises a 12-17 Volt DC signal.
 10. Amobile vehicle platform comprising: a vehicle body; a mobile powersystem carried by said vehicle body and comprising an alternatingcurrent-direct current (AC-DC) converter configured to convert a grid ACsignal to a power limited DC charging signal, at least one DC-ACconverter coupled to said AC-DC converter, a battery module configuredto provide a DC power signal, a switching circuit coupled between saidbattery module, and said AC-DC converter and said at least one DC-ACconverter, said switching circuit comprising a switch, and first andsecond diodes coupled in parallel to said switch, and a controllercoupled to said battery module, said switching circuit, and said atleast one DC-AC converter, said controller configured to selectivelyswitch said switching circuit between a first state, a second state, anda third state, the first state comprising one of concurrently chargingsaid battery module using the power limited DC charging signal androuting the DC power signal to said at least one DC-AC converter, orproviding the DC power signal using said battery module without thepower limited DC charging signal the second state comprising chargingsaid battery module using the power limited DC charging signal anddisabling said at least one DC-AC converter, the third state comprisingblocking charging of said battery module and routing the DC power signalto said at least one DC-AC converter; and a plurality of loads carriedby said vehicle body and powered by said mobile power system.
 11. Themobile vehicle platform of claim 10 wherein said switching circuitcomprises a current limiting element coupled between said battery moduleand said second diode.
 12. The mobile vehicle platform of claim 10wherein said first diode has an anode terminal coupled to a cathodeterminal of said second diode.
 13. The mobile vehicle platform of claim10 wherein said at least one DC-AC converter comprises a first DC-ACconverter configured to generate a first AC power signal, and a secondDC-AC converter configured to generate a second AC power signal, thesecond AC power signal having a voltage level less than that of thefirst AC power signal.
 14. The mobile vehicle platform of claim 13wherein said mobile power system includes first and second ACdistribution circuits respectively coupled to said first DC-AC converterand said second DC-AC converter, each of said first and second ACdistribution circuits configured to deliver a plurality of AC signalsrespectively to said plurality of loads.
 15. The mobile vehicle platformof claim 14 wherein said plurality of loads have a cumulative powerrating greater than 4.8 kW.
 16. The mobile vehicle platform of claim 10wherein said controller comprises a battery management device configuredto monitor a plurality of parameters related to said battery module. 17.The mobile vehicle platform of claim 16 wherein the plurality ofparameters comprises a total voltage value, voltage values of individualbattery cells, a temperature value, a state of charge (SOC) value, astate of health (SOH) value, and a current value.
 18. A method formaking a mobile power system, the method comprising: coupling analternating current-direct current (AC-DC) converter configured toconvert a grid AC signal to a power limited DC charging signal; couplingat least one DC-AC converter to the AC-DC converter; coupling a batterymodule configured to provide a DC power signal; coupling a switchingcircuit between the battery module, and the AC-DC converter and the atleast one DC-AC converter, the switching circuit comprising a switch,and first and second diodes coupled in parallel to the switch; andcoupling a controller to the battery module, the switching circuit, andthe at least one DC-AC converter, the controller configured toselectively switch the switching circuit between a first state, a secondstate, and a third state; the first state comprising one of concurrentlycharging the battery module using the power limited DC charging signaland routing the DC power signal to the at least one DC-AC converter, orproviding the DC power signal using the battery module without the powerlimited DC charging signal; the second state comprising charging thebattery module using the power limited DC charging signal and disablingthe at least one DC-AC converter; the third state comprising blockingcharging of the battery module and routing the DC power signal to the atleast one DC-AC converter.
 19. The method of claim 18 wherein theswitching circuit comprises a current limiting element coupled betweenthe battery module and the second diode.
 20. The method of claim 18wherein the first diode has an anode terminal coupled to a cathodeterminal of the second diode.